BEIJING — North Korean leader Kim Jong Il reportedly arrived in eastern China by train Sunday on his third trip in about a year to his country's main ally, and a Chinese leader told South Korea's president Beijing invited Kim to learn from Chinese reforms.

Kim, whose rare foreign trips are cloaked in secrecy, arrived late in the evening at Yangzhou's train station, reported the Yonhap news agency and YTN television network, both citing unidentified sources in the city west of Shanghai. Yonhap said he was expected to travel to a guesthouse by vehicle, and YTN said he was expected to stay in the city about three days.

Meeting in Japan, Chinese Premier Wen Jiabao told South Korean President Lee Myung-bak that Beijing invited Kim to study China's economic reforms, Lee's office said in a statement. It did not say whether Wen confirmed Kim's arrival in China.

"We invited (Kim) to give (the North Koreans) a chance to understand the Chinese development and use it for their own development," Wen was quoted as saying.

Kim rarely travels abroad, and his visits to China are seen as a means to shore up support for his isolated government and faltering economy. North Korea in January appealed for urgent aid to feed its population and faces international pressure to end its nuclear weapons program.

China and North Korea want to resume the six-nation talks on the North's nuclear program, while fellow participants South Korea and the United States say the North must first exhibit sincerity toward disarmament.

The U.S. State Department says it has no information on North Korean officials visiting China. U.S. officials plan to visit the North starting Tuesday to evaluate its food needs. The U.N. says 6 million people — a quarter of the North's population — need emergency help after bad weather hit crops.

North Korean and Chinese official media have been silent about Kim's travels, and China has confirmed his most recent official visits — in last May and August — only after Kim returned home.

A visit to Yangzhou, a tourist spot on the Yangtze River, could have special symbolism for Kim. It would come 20 years after Chinese state media say his father and predecessor, North Korean founder Kim Il Sung, held talks there with China's then-president, Jiang Zeming.

South Korean broadcaster YTN said Kim would visit sites in Yangzhou linked to the solar power industry. It said he also plans to travel to Shanghai, which he visited in 2001 to look at China's economic reforms.

On Saturday, Kim visited the industrial center of Changchun, Yonhap said. He met there in August with Chinese President Hu Jintao.

Japanese public broadcaster NHK obtained a grainy video appearing to show Kim in the northeastern Chinese city of Mudanjiang on Friday. He was shown shaking hands and waving to Chinese officials before climbing into a limousine.

South Korean media had initially suggested Kim's son and heir apparent, Kim Jong Un, was either making a trip to China alone or was accompanying his father.